Watson & Friend.(1969) is as follows.
Watson, D., & Friend, R. (1969). Measurement of social-evaluative anxiety. Journal of Consulting & Clinical Psychology, 33(4), 448. doi:10.1037/h0027806.
Since Watson & Friend.(1969), Many researchers have studied the association between social anxiety and fear of negative evaluation. However, a research team consisting of Adult Anxiety Clinic of Temple University and Department of Psychology in Washington University developed The Fear of Positive evaluation scale(FPES) to assess fear of receiving praise in undergraduate students(Weeks et al., 2008).
Weeks et al.(2008) is as follows.
Weeks et al.(2008) found the FPES correlated positively with measures of social interaction anxiety and fear of negative evaluation. The results of their study show that fear of positive evaluation and fear of negative evaluation are separate constructs. Therefore, social anxiety may be related to not only fear of criticism but also fear of praise.
On the other hand, many children with selective mutism are socially anxious or have social anxiety disorder(also known as social phobia). Although not every selectively mute child has high level of social anxiety, it is possible that they are afraid of positive evaluation.
However, there is no research surveying fear of positive evaluation as well as fear of negative evaluation possibly underlying selective mutism. All we need is study！